EP0371754A2 - Pneumatique radial - Google Patents

Pneumatique radial Download PDF

Info

Publication number
EP0371754A2
EP0371754A2 EP89312349A EP89312349A EP0371754A2 EP 0371754 A2 EP0371754 A2 EP 0371754A2 EP 89312349 A EP89312349 A EP 89312349A EP 89312349 A EP89312349 A EP 89312349A EP 0371754 A2 EP0371754 A2 EP 0371754A2
Authority
EP
European Patent Office
Prior art keywords
belt
cords
central part
lateral parts
rigidity
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP89312349A
Other languages
German (de)
English (en)
Other versions
EP0371754A3 (fr
EP0371754B1 (fr
Inventor
Kazuhiko Kawamura
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Rubber Industries Ltd
Original Assignee
Sumitomo Rubber Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Rubber Industries Ltd filed Critical Sumitomo Rubber Industries Ltd
Publication of EP0371754A2 publication Critical patent/EP0371754A2/fr
Publication of EP0371754A3 publication Critical patent/EP0371754A3/fr
Application granted granted Critical
Publication of EP0371754B1 publication Critical patent/EP0371754B1/fr
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
    • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
    • B60C9/22—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel the plies being arranged with all cords disposed along the circumference of the tyre
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60C—VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
    • B60C9/00—Reinforcements or ply arrangement of pneumatic tyres
    • B60C9/18—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers
    • B60C9/20—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel
    • B60C9/2003—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel characterised by the materials of the belt cords
    • B60C9/2009—Structure or arrangement of belts or breakers, crown-reinforcing or cushioning layers built-up from rubberised plies each having all cords arranged substantially parallel characterised by the materials of the belt cords comprising plies of different materials

Definitions

  • the present invention relates to a radial tyre for heavy duty and high speed vehicles which is improved in durability of the tread portion.
  • the tread portion is suddenly swollen by centrifugal force.
  • a large deflection of about 25 to 35% is caused in the radial direction of the tyre by the impact of landing.
  • the present invention is based on the discovery that the distribution of the amount of tread lift by the superhigh speed rotation, affects the superhigh speed durability, and that by making the amount of lift in the tread shoulders smaller than that in the tread crown, temperature rise in the tread shoulders and the beads is lessened, and the high speed durability is improved. Also this results in a lowering of bead durability problems due to large load in low speed running.
  • a heavy duty high speed radial tyre comprising a radial carcass having at least one ply of cords arranged at an angle of 70 degrees to 90 degrees to the equator (CO) of the tyre and turned up at both edges around bead cores to be secured thereto, and a belt composed of a plurality of plies of parallel cords arranged at an angle of 0 degrees to 15 degrees to the tyre equator (CO) wherein the 1000 kgf rigidity of the belt is smaller in the central part (C) than in the lateral parts (S) where the 1000 kgf rigidity is defined as the ratio of the force to the resultant elongation when the belt is circumferentially pulled by a force of 1000 kgf per unit axial width of 1 cm.
  • the bulge-out in the lateral or shoulder parts of the tread is made smaller than that in the central part.
  • the temperature rise of the tyre in the lateral parts is restricted.
  • the stress acting on the bead portions is lessened, and the temperature rise in the bead portions is as a result also lowered, so that the bead durability is enhanced.
  • the invention can contribute to prevention of bead damage in the heavy load condition such as the taxi condition, and also to an improvement in the general durability of the tread and bead portions.
  • the heavy load durability is also enhanced.
  • the bulge-out of the lateral parts is larger than that of the central part, the strain in the lateral parts increases to raise the temperature, and the increase in the strain in the lateral parts causes an increase in the strain in the bead portions and in the heat generation, and as a result the bead durability is impaired.
  • the 1000 kgf rigidity R is varied between the central part and the lateral parts without making a weight difference between them.
  • the increase in the bulge-out of the central part is effective to restrict the occurrence of a standing wave in the tyre at high speed.
  • the tyre 1 of the invention is an aircraft radial tyre of size 45x17 R20 inflated to its regular pressure.
  • the tyre 1 has a pair of bead portions 3 with a bead core 2, a sidewall portion 4 extending radially outwardly from each bead portion, and a tread portion 5 extending between the outer ends of the sidewall portions.
  • the tyre is provided with a radial carcass 7 extending between the bead portions 3 through the sidewall portions 4 and the tread portion 5.
  • the carcass 7 is composed of an inner layer 7A and an outer layer 7B.
  • the inner layer 7A consists of a plurality of, for example, four carcass plies 7a turned up around the bead cores 3 from the axially inside to the outside thereof.
  • the outer layer 7B consists of a plurality of, for example, two carcass plies 7b extending along the outside of the turned up portion of the inner layer 7A and turned up around the bead cores 3 from the outside to the inside thereof.
  • the carcass cords are laid radially at an angle of 70 degrees to 90 degrees to the equator of the tyre, and the carcass cords are inclined reversely between the adjacent carcass plies with respect to the radial direction of the tyre so as to cross with each other.
  • a covering layer 8 is disposed between the carcass 7 and each bead core 3 to prevent the carcass from abrasion due to its movements around the bead core 2 along with the repeated deformation of the tyre.
  • a bead apex 9 made of a tapered rubber member extending radially outwardly over the upper end of the covering layer 8 is disposed, thereby dispersing the stress of the carcass 7 turned up portions due to its deflection.
  • the bead apex 9 is composed of a hard rubber forming a lower part 9A and a soft rubber forming an upper part 9B. It is also possible to provide a chafer (not shown) for preventing rim chafing on the outer surface of the bead 3.
  • a belt 10 is disposed radially outside the carcass 7 and inside a rubber tread, and further in this embodiment a cut breaker 14 is disposed between the belt and the carcass.
  • the belt 10 is composed of a plurality of, for example, eight plies 10a.
  • the belt width W10 between the outermost edges (a) is in the range of about 70 to 85% of the tyre overall section width W.
  • the surface of the outer edge is formed in parallel with the outer surface SB of the tyre, and the minimum distance between the outer edge and the outer surface SB is set in a range of 3 to 8 mm.
  • the width W10 of the belt is wider than the width of the cut breaker 14 which is composed of two plies 14a, a narrower outside ply and a wider inside ply.
  • the belt 10 is provided with different 1000 kgf rigidities Rc and Rs between the central part C centred on the tire's equator CO and the lateral parts S located one on each side of the central part, and the 1000 kgf rigidity Rs in the lateral parts S is larger than the 1000 kgf rigidity Rc in the central part C, and the Rs/Rc ratio is not less than 1.2 and not more than 3.0.
  • the 1000 kgf rigidity is defined as the ratio of the force to the resultant elongation when the belt is circumferentially pulled by a force of 1000 kgf per unit axial width of material of 1 cm.
  • each lateral part S is defined between each of the outermost edges (a) and a position a distance LS inward thereof in the axial direction of the tyre, and the distance LS is more than 1/5 and less than 1/3 times the above-mentioned overall width W10 of the belt 10.
  • a transitional part V for which the 1000 kgf rigidity Rv is between Rs and Rc is preferably formed.
  • Figure 3(a) shows an example of the belt, in which some of the belt plies 10a, the second and fourth belt plies re each composed of a central strip 10aC having a lower rigidity and two lateral strips 10aS having a higher rigidity jointed one on each side of the central strip, whereby the 1000 kgf rigidity is turned at their joints K.
  • Figure 3(b) shows another example of the belt, in which the first to fourth plies are composed of a central strip 10aC and lateral strips 10aS, and their joints K are shifted in the axial direction of the tyre so that the joints in the second and fourth plies are located axially inwards of the joints in the first and third plies.
  • Figure 3(c) shows a modification of the belt shown in Figure 3(b), in which the joints K are gradually shifted so that the further radially inwards the ply is located then the further axially outwards the joint is located.
  • the transitional part V is formed between the axially outermost joint and the innermost joint.
  • the transitional part V can be formed.
  • organic fibre cords such as nylon, polyester, or aromatic polyamide are preferably used for the belt.
  • hybrid cords made of different organic fibre materials can be used.
  • an organic fibre cord having a so-called skin core structure comprising a core made of polyester filaments and an outside part, that is a skin, made of nylon filaments, is preferably used.
  • the rigidity and the heat shrink properties are from the polyester core, and good adhesion is provided by the nylon skin.
  • the nylon is Nylon 6, and the blending ratio (polyester/nylon) of the polyester filaments to nylon filaments is preferably not less than 30/70 and not more than 10/90.
  • the rigidity difference is formed by changing the cord end count, and in this case the ratio Ts/Tc of the count Ts in the lateral parts S to the count Tc in the central part C is in the range of 1.1 to 3.0.
  • the count is expressed by the number of cords per 5 cm width in the axial direction of the tyre. If the ratio Tc/Ts is smaller than 1.1, it is difficult to provide the above-mentioned rigidity difference.
  • the cords are located too closely to each other so as to lower the bonding strength with the rubber, or the cords are too scarce in the central part C or in the central strip 10aC so as to excessively lower the rigidity of the central part.
  • the rigidity difference can be formed by changing the initial modulus of elasticity.
  • the ratio Es/Ec of the initial modulus of elasticity Es of the cords used in the lateral strip to the initial modulus of elasticity Ec of the cords used in the central strip C is set in the range of 1.1 to 2.0.
  • the initial modulus of elasticity is specified as in JIS-L1017, and it is defined as the modulus of elasticity at the origin of the load-­elongation curve. To vary the initial modulus of elasticity, the cord thickness, treatment, and/or the number of twists should be changed.
  • the ratio Ds/Dc of the thickness Ds of the cords used in the lateral strip 10aS to the thickness Dc of the cord used in the central strip 10aC is set in a range of 1.1 to 1.5. If the ratio is smaller than 1.1, it is difficult to have a specified difference in the 1000 kgf rigidity R between the outside part S and middle part C. If exceeding 1.5, the difference in thickness becomes excessive between the adjacent strips 10aS and 10aC, and deviation is likely to take place due to tyre inflation, and the uniformity in the axial direction of the tyre is impaired
  • the 1000 kg rigidity Rs of the lateral parts S can be set larger than the 1000 kgf rigidity Rc of the central part C.
  • the cord count ratio Rs/Tc, the initial modulus ratio Es/Ec, and/or the cord thickness ratio Ds/Dc can be selectively limited in the above-mentioned ranges regardless of cord materials.
  • the decrease in the strain in the lateral parts S also contributes to a reduction in the compressive stress of the carcass cords caused around the upper edge of the rim flange when the bead portion is bent.
  • This lessened strain ply separation and breakage can be prevented, and heat generation is lowered to improve bead durability. This is effective also to improve the large load durability in the taxi condition as mentioned above.
  • the increase in the bulge-out amount in the central part increases the apparent rigidity in this part, and this contributes to the suppression of standing waves.
  • an auxiliary layer 20 can be disposed on the lateral parts of the belt to further enhance the circumferential rigidity of those part.
  • Test tyres of size 46x10 R20 were experimentally fabricated according to the specifications given in Table 1 and the structure shown in Figure 1, and tested for durability, and temperature rise in the lateral part and bead portion. The test results are shown in Table 1.
  • each tyre was inflated to its regular pressure and loaded to 150% of the normal load, and then a take-off simulation test was conducted by using a drum tester at a rotating speed corresponding to 300 km/h.
  • the temperature of the lateral part was measured near the belt edge, and the bead temperature was measured at a position axially inward of a contact point where the outside of the bead starts to contact with the rim flange and near the inside reinforcement layer.
  • the bulge-out in the lateral parts is reduced, and accordingly the strain acting on the bead portions is reduced, so that both high speed durability and large load durability can be improved.
  • Example 1 Reference Carcass Nylon Nylon Nylon Belt Material Nylon Nylon Nylon Nylon LS/W 0.4 0.4 ---- Central part Thickness 1680d 1680d 1680d Count 36 ends/5cm 32 ends/5cm 36 ends/5cm Elongation at 15 kgf 10 % 12 % 10 % Lateral part Thickness 1890d 1890d 1680d Count 39 ends/5cm 39 ends/5cm 36 ends/5cm Elongation at 15 kgf 7 % 6 % 10 % Rs/Rc 1.5 2.0 1.0 Temperature Shoulder 94 o C 80 o C 112 o C Bead 123 o C 112 o C 135 o C Durability 115 130 100

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Tires In General (AREA)
EP19890312349 1988-11-30 1989-11-28 Pneumatique radial Expired - Lifetime EP0371754B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP63302974A JPH02147406A (ja) 1988-11-30 1988-11-30 重荷重高速ラジアルタイヤ
JP302974/88 1988-11-30

Publications (3)

Publication Number Publication Date
EP0371754A2 true EP0371754A2 (fr) 1990-06-06
EP0371754A3 EP0371754A3 (fr) 1991-02-20
EP0371754B1 EP0371754B1 (fr) 1994-03-02

Family

ID=17915403

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890312349 Expired - Lifetime EP0371754B1 (fr) 1988-11-30 1989-11-28 Pneumatique radial

Country Status (3)

Country Link
EP (1) EP0371754B1 (fr)
JP (1) JPH02147406A (fr)
DE (1) DE68913449T2 (fr)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0600398A1 (fr) * 1992-12-01 1994-06-08 Uniroyal Englebert Reifen GmbH Bandage pneumatique ayant une ceinture à propriétes asymmétriques
EP0978396A2 (fr) * 1998-08-03 2000-02-09 Continental Aktiengesellschaft Bandage pneumatique pour véhicule
US9272577B2 (en) 2011-06-13 2016-03-01 The Goodyear Tire & Rubber Company Aircraft radial tire

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2958359A (en) * 1957-01-10 1960-11-01 Michelin & Cie Pneumatic tire casing
FR2351809A1 (fr) * 1976-05-17 1977-12-16 Pirelli Perfectionnement a la structure resistante des pneumatiques pour roue de vehicule
GB2015937A (en) * 1978-03-09 1979-09-19 Pirelli Radial tyre breaker assemblies

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6160305A (ja) * 1984-09-03 1986-03-28 Sumitomo Rubber Ind Ltd 航空機用ラジアルタイヤ

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2958359A (en) * 1957-01-10 1960-11-01 Michelin & Cie Pneumatic tire casing
FR2351809A1 (fr) * 1976-05-17 1977-12-16 Pirelli Perfectionnement a la structure resistante des pneumatiques pour roue de vehicule
GB2015937A (en) * 1978-03-09 1979-09-19 Pirelli Radial tyre breaker assemblies

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0600398A1 (fr) * 1992-12-01 1994-06-08 Uniroyal Englebert Reifen GmbH Bandage pneumatique ayant une ceinture à propriétes asymmétriques
EP0978396A2 (fr) * 1998-08-03 2000-02-09 Continental Aktiengesellschaft Bandage pneumatique pour véhicule
EP0978396A3 (fr) * 1998-08-03 2001-08-16 Continental Aktiengesellschaft Bandage pneumatique pour véhicule
US9272577B2 (en) 2011-06-13 2016-03-01 The Goodyear Tire & Rubber Company Aircraft radial tire

Also Published As

Publication number Publication date
EP0371754A3 (fr) 1991-02-20
DE68913449D1 (de) 1994-04-07
JPH02147406A (ja) 1990-06-06
DE68913449T2 (de) 1994-06-01
EP0371754B1 (fr) 1994-03-02

Similar Documents

Publication Publication Date Title
EP0947358B1 (fr) Pneu radial pour vehicules lourds
US5476129A (en) Radial tire for aircraft with specified bead portions
EP0958946B1 (fr) Bandage pneumatique radial destiné aux poids-lourds
EP0346106A1 (fr) Bandage pneumatique
EP0736400B1 (fr) Pneumatiques à carcasse radiale pour poids lourds
US6279635B1 (en) Heavy duty pneumatic radial tires with bead portion reinforcing layer having multiple inclination angles
US5335707A (en) High speed heavy duty cross ply tire
US6823914B2 (en) Heavy duty pneumatic radial tires with organic fiber cord bead reinforcing layer
EP0435622B1 (fr) Pneumatique à grande vitesse pour poids lourds
JP2899198B2 (ja) 高速重荷重用タイヤ
EP0295348B1 (fr) Bandages pneumatiques radiaux pour avions
US5522443A (en) High speed heavy duty tire and rim assembly whose tire includes a buffer layer in each bead portion
JPH07112763B2 (ja) 空気入りラジアルタイヤ
US4705091A (en) Heavy duty pneumatic radial tires
EP0698513B1 (fr) Bandage pneumatique radial
EP0413574A2 (fr) Pneumatique radial pour grandes vitesses
GB2198996A (en) Radial tyres
EP0407071B1 (fr) Pneumatique radial, haute vitesse, grande charge
EP0371754B1 (fr) Pneumatique radial
EP0661180A1 (fr) Bandage pneumatique radial pour véhicules de tourisme
JP2786804B2 (ja) 高速重荷重用タイヤ
JP2786805B2 (ja) 高速重荷重用タイヤ
EP0243558B1 (fr) Pneumatique radial pour usage sous fortes charges
EP0435621B1 (fr) Pneumatique à grande vitesse pour poids lourds
EP0392117B1 (fr) Bandage pneumatique

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE FR GB

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE FR GB

17P Request for examination filed

Effective date: 19901221

17Q First examination report despatched

Effective date: 19920805

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB

REF Corresponds to:

Ref document number: 68913449

Country of ref document: DE

Date of ref document: 19940407

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20061108

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20061122

Year of fee payment: 18

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 20061123

Year of fee payment: 18

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20071128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20080603

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20080930

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20071128

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20071130